Kathleen Turner and Michael Douglas play a married couple who battle in the 1989 movie 'War of the Roses.' / Francois Duhamel, 20th Century Fox

by Kim Painter, Special for USA TODAY

by Kim Painter, Special for USA TODAY

People who are constantly at odds with their families, friends and neighbors are more likely to die in middle age, a big new study from Denmark finds.

The study provides some broad new evidence for what other researchers have found on a smaller scale: Too much arguing is bad for your health.

The Danish researchers, reporting Thursday in the Journal of Epidemiology & Community Health, also found that people who worry a lot about partners and children or say those family members "demand too much" have a higher risk of dying young.

The study is a reminder that while close relationships can confer health benefits, they also may come with health risks, says lead author Rikke Lund, a public health researcher at the University of Copenhagen. "That tends to be overlooked," she says.

Lund and colleagues asked nearly 10,000 men and women ages 36 to 52 how often they "experience conflict" with partners, children, other family members, friends and neighbors. They also asked about worries and demands in those relationships.

The researchers checked death records 11 years later and found that frequent fighters were two to three times more likely than their more peaceable peers to be dead already - even if their fights were mostly with neighbors, not friends or family. "That surprised me," Lund says.

Those who often worried about or felt pressured by kids and partners (but not other family members, friends or neighbors) also were more likely to have died..

The causes of death for the 4% of women and 6% of men who died were the usual for middle-age: most often cancer, followed by heart disease and stroke, liver disease, accidents and suicide.

The links between conflict and death held up even when the researchers accounted for factors including gender, social class, depressive symptoms and social support.

Still, the study does not prove arguing directly harms health. It is likely that certain personality traits, not measured in the study, contribute both to argumentative behavior and early death, says Carolyn Aldwin, a researcher who studies adult development and aging at Oregon State University. She was not involved with the new study.

"We've known for a long time that hostility has a big effect on cardiovascular disease and mortality," Aldwin says. Expressing hostility through frequent conflict may make things worse, she says, and the new study "makes a very strong case that all the stresses they talk about are linked with mortality."

Some other studies have shown that arguing can have direct, negative effects on the body, says Janice Kiecolt-Glaser, a professor of psychiatry and psychology at Ohio State University. She also was not involved in the report from Denmark. In one study, she and her colleagues inflicted small wounds on the arms of married couples and then had the couples either argue or have more pleasant conversations. The arms healed more slowly after the fights.

Inflammation, linked with diseases from cancer to heart disease, may be one important physiological link between stress in relationships and poor health, Kiecolt-Glaser says.

"There are also indirect, behavioral links," she says. "When we are stressed, we don't sleep as well, we have poorer diets. ... We tend to drink more and exercise less."

So could arguing less save your life?

"It seems from this study that it would be a good idea to reduce the amount of conflict in your life," Lund says. "But I'm not a therapist. I'm just looking at these statistical associations."